<template>
  <!-- 头部区域 -->
  <el-container class="home-container">
    <el-header>
      <div>
        <img src="../assets/heima.png" />
        <span>后台电商管理系统</span>
      </div>
      <el-button type="info" @click="logout">退出</el-button>
    </el-header>
    <!-- 页面主体区域 -->
    <!-- 侧边栏菜单区域 -->
    <el-container>
      <!-- 侧边栏 -->
      <el-aside :width="isCollapse ? '64px' : '200px'">
        <!-- 点击实现折叠,展开效果 -->
        <div class="toggle-button" @click="isCollapse = !isCollapse">|||</div>
        <!-- 侧边栏效果 -->
        <!--
          unique-opened 只允许展开一个子菜单
          collapse 是否水平折叠菜单
          collapse-transition 开关折叠动画
          router 开启路由模式,完成子页面的跳转
          default-active 点击激活高亮(当前被选中的index)
         -->
        <el-menu
          background-color="#333744"
          text-color="#fff"
          active-text-color="#409eff"
          unique-opened
          :collapse="isCollapse"
          :collapse-transition="false"
          router
          :default-active="$route.path"
        >
          <!-- 一级菜单 -->
          <el-submenu
            :index="item.id + ''"
            v-for="item in menuList"
            :key="item.id"
          >
            <!-- 一级菜单模板区域 -->
            <template slot="title">
              <!-- 图标 -->
              <i :class="iconsObj[item.id]"></i>
              <!-- 文本 -->
              <span>{{ item.authName }}</span>
            </template>
            <!-- 二级菜单 -->
            <!-- 利用 :index 属性指定要跳转的页面,并手动补齐 '/' -->
            <el-menu-item
              :index="'/' + subItem.path"
              v-for="subItem in item.children"
              :key="subItem.id"
              @click="saveNavMenu('/' + subItem.path)"
            >
              <!-- 图标 -->
              <i class="el-icon-menu"></i>
              <!-- 文本 -->
              <span>{{ subItem.authName }}</span>
            </el-menu-item>
          </el-submenu>
        </el-menu>
      </el-aside>
      <!-- 右侧主体区域 -->
      <el-main>
        <!-- 欢迎组件路由占位符 -->
        <router-view></router-view>
      </el-main>
    </el-container>
  </el-container>
</template>

<script>
export default {
  data () {
    return {
      // 获取到的菜单数据
      menuList: [],
      // 字体图标
      iconsObj: {
        125: 'iconfont  icon-users',
        103: 'iconfont  icon-tijikongjian',
        101: 'iconfont  icon-shangpin',
        102: 'iconfont  icon-danju',
        145: 'iconfont  icon-baobiao'
      },
      isCollapse: false,
      // 当前激活的路径
      activePath: sessionStorage.activePath
    }
  },
  created () {
    this.getMenuList()
    this.activePath = sessionStorage.activePath
  },
  methods: {
    // 实现退出功能
    logout () {
      // 1. 清空token
      window.sessionStorage.clear()
      // 2. 跳转到登录页
      this.$router.push('/login')
    },
    // 获取所有菜单
    async getMenuList () {
      const { data: res } = await this.$http.get('menus')
      if (res.meta.status !== 200) return this.$message.error(res.meta.msg)
      this.menuList = res.data
    },
    // 将当前路径保存到 sessionStorage 中
    saveNavMenu (active) {
      this.activePath = active
      sessionStorage.activePath = active
    }
  }
}
</script>

<style lang="less" scoped>
// 实现页面样式全屏
.home-container {
  height: 100%;
}
.el-header {
  padding-left: 0;
  background-color: #373d41;
  display: flex;
  // flex布局的左右贴边
  justify-content: space-between;
  align-items: center;
  color: #fff;
  font-size: 20px;
  > div {
    display: flex;
    align-items: center;
    span {
      margin-left: 15px;
    }
  }
}
.el-aside {
  background-color: #333744;
  .el-menu {
    border-right: none;
  }
}
.el-main {
  background-color: #eaedf1;
}
.iconfont {
  margin-right: 10px;
}

.toggle-button {
  background-color: #4a5064;
  font-size: 10px;
  line-height: 24px;
  color: #fff;
  text-align: center;
  // 文字间距为 0.2em
  letter-spacing: 0.2em;
  cursor: pointer;
}
</style>
